A urine analyzer provided with a washing means for washing a urine flow path is known, which includes a nozzle. After urine has been suctioned for examination from the nozzle and the urine has been completely titrated from the nozzle to a reagent pipette, the urine is examined based on the reaction in the reagent pipette. The urine analyzer is further provided with a concentration detection means for detecting the concentration of a specific component contained in the urine suctioned from the nozzle, and a washing capacity control means for varying the washing capacity of the washing means based on the detection result of the concentration detection means (for example, Japanese Laid-Open Patent Publication No. 2000-321270).
A washing device for a dispensation injection nozzle is known that is provided with an ultrasonic wave generating means for generating ultrasonic wave vibrations while optionally changing the position of the node on the dispensation injection nozzle without generating a node of the ultrasonic vibration in the dispensation injection nozzle that suctions and discharges a sample. The dispensation injection nozzle is vibrated to dislodge sample adhered to the inner surface and outer surface of the dispensation injection nozzle from the dispensation injection nozzle (for example, Japanese Laid-Open Patent Publication No. H5-1983).
A pipette washing device provided with a trough for accommodating water for washing is known provided with a brush arranged inside the trough, a magnetic body mounted on the bottom part of the brush, a rotating magnetic body having the same polarity as the magnetic body mounted on the bottom of the brush, and a drive means for rotating the rotating magnetic body (for example, Japanese Utility Model Publication No. H6-15772).
In sample analyzers which suction a sample from a nozzle (pipette) such as those described above, the nozzle must be washed before suctioning the next sample. Analysis of the next sample may be adversely affected if the nozzle is inadequately washed.
To solve this problem, in the urine analyzer disclosed in the above-mentioned Japanese Patent Publication No. 2000-321270, the number of washings or the amount of washing fluid used is changed in accordance with the detection result obtained by the concentration detection means. However, if the number of washings is increased, the processing capability of the device is markedly reduced. If the amount of washing fluid used is increased, the operating cost of the device is increased. Furthermore, this urine analyzer is provided with a concentration detection means for changing the washing capability, which also increases the size of the device.
The devices disclosed in Japanese Laid-Open Patent Publication No. H5-1983 and Japanese Utility Model Publication No. H6-15772 also result in larger devices similar to the device described in Japanese Patent Publication No. 2000-321270.